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Theft of iPhones, MP3 players or laptop computers now accounts for one in six of all crimes in London.

Police say thieves and burglars increasingly target the latest gadgets, in particular the new iPhone 5.

But while the number of such thefts has grown six per cent, crime in general in the capital is down by three per cent.

Muggings as a whole are down four per cent, but officers say they are dealing with a spate involving thieves on bikes snatching phones from people using them in the street.

Detective constable Adele Cashman, 30, who collapsed and died in Camden this week, was chasing a mugging suspect after a woman was robbed of her smartphone.

Latest figures show 139,345 cases of theft, burglary and robbery where phones, laptops or MP3 players were stolen from October last year to September this year. This compares with 131,506 reported offences in the same period the year before.

Cases involving the theft of phones and handling stolen phones rocketed by 19 per cent. Sources say iPhones now account for about half of all phones stolen in London.

Metropolitan Police Commissioner Bernard Hogan-Howe said recently a surge in robberies was driven by the theft of mobile electronic devices. When new models come out, he said, it “creates a market” for thieves.

Phones are often passed to handlers who ship them abroad. They can fetch about £200 in countries such as Algeria and India. Police are using iPad apps to trace phones that have tracking devices, although most phones are switched off after being snatched. The Met is in talks with Apple about new measures to make iPhones less attractive to thieves.

Professor Keith Hayward, a criminologist at the University of Kent, said: “This spike in theft of portable items is most obviously down to the cost of these goods substantially increasing...so their desirability and resale value has also risen.”